The early stages of an election campaign often resemble what journalists call the 'silly season'. Expecting excitement but not really finding any, political reporters create their own. The pursuit of Liberal Democrat leader Tim Farron over his views on homosexuality was a good example of this. It was a good story – liberal party leader has illiberal views – but one that made me uncomfortable.

Initially, and the question had been put before, Farron simply declined to answer, hiding behind generalities ('we're all sinners') and obviously hoping it would go away. In the midst of an election campaign, however, such things come back to haunt party leaders, and he had little choice but to come up with something more concrete. It was a very 'bubble' incident, arguably of more interest to what populists denigrate as the 'metropolitan' media than actual voters, but it struck me as intolerant, particularly as it came from the sort of people who rightly bemoan such things.

Now I am gay, but I find it almost impossible to get upset about others, even politicians, disapproving of my sexuality on the basis of their faith. I disagree, of course, but as on other 'conscience' issues like abortion, surely any democratic society can tolerate a range of views? Just so long as they're expressed moderately and don't generate hypocrisy (Farron, for example, has long supported LGBT legislation in parliament). Interviewed on the BBC last Sunday, the Liberal Democrat leader made the eminently reasonable point that voters who wanted 'strong' opposition to the Conservatives didn't have to agree with him on 'everything'. Amen to that.

Boris Johnson's description of Jeremy Corbyn as a 'mutton-headed old mugwump' was another feature of this election's phony war, although I was quietly smug in actually knowing what 'mugwump' meant before the lexicologists got to work. My first political column in the Gaudie, Aberdeen University's student newspaper, was entitled 'Mugwump' (although I'd be embarrassed to read it now), as was a short-lived blog I produced more recently. I forget where I first came across the term, but it means a person who remains 'aloof' or independent, especially from party politics.

Which made the foreign secretary's use of it in relation to the left-wing leader of the Labour party rather curious. 'Mutton-headed', perhaps, but a 'mugwump'? Still, in a campaign increasingly dominated by vapid slogans like 'strong and stable leadership' and 'coalition of chaos', Johnson's intervention at least livened things up. I've heard media colleagues complaining about the prime minister's constant use of those sound-bites, but we're not the target audience. Like it or not, such phrases repeated over and over again, especially on television, eventually imprint themselves on voters' minds.

Lynton Crosby, the so-called 'wizard of Oz', apparently calls this 'scraping the barnacles', where a party's message is honed down to its absolute essence and then articulated ad nauseam. It's the same technique used by the SNP, thus Nicola Sturgeon is saying over and over again that voters mustn't allow the wicked Tories to do 'anything they want' to Scotland if they get a bigger majority on 8 June. Alex Salmond, meanwhile, has been railing against commentators again, this time denigrating Scotland on Sunday's Euan McColm as an 'ultra-unionist' – another new contribution to the Scottish political lexicon.

Predictably, boring old policy has yet to penetrate the rhetorical battle, not least because the SNP isn't exactly strong on the domestic front and the newly-revived Scottish Conservatives don't have any beyond opposition to a second referendum. As a recent Daily Record/Google survey poll confirmed to no one's surprise, what matters in this election is the 'I' word. Even Nicola Sturgeon has given up trying to pretend otherwise, her attempt to decouple the election from independence having floundered given her recent demand for a re-run of September 2014.

It's striking, meanwhile, that this SNP election campaign has none of the breezy, upbeat quality of previous contests. Indeed, this one is rather bleak, the first minister warning of Brexit 'chaos', an 'increasingly hard-line' Tory government rampaging across Scotland, and so on. All Ms Sturgeon can offer as an alternative is SNP MPs providing a 'strong voice' and 'real opposition' at Westminster. Those of a 1980s vintage might recall Nationalist scorn when Scottish Labour MPs made a similar pitch at the 1987 general election. What was it Mr Salmond called Donald Dewar et al? The 'feeble 50'.

Equally striking is the fact that all three Unionist parties are basically running the same campaign: opposition to a second independence referendum and implorations to the SNP to 'get on with the day job' and to voters to 'send a message' to Nicola Sturgeon. The trouble for Labour and the Liberal Democrats, however, is that the Scottish Tories got there first and therefore Ruth Davidson 'owns' that particular narrative. Indeed, I can't recall the Conservatives being this confident going into a Westminster election. The question is, will that confidence translate into seats?
David Torrance will be contributing a weekly Election Notebook